Method of centering lenses.



No. 834,020. PATENTED OCT; 23, 1906.

A. FELLOW.

- METHOD OF GENTERINGLENSES APPLICATION FILED APB.24.1.9Q5.

3 SHEETS-SHEET 1- wituza ouo No. 834,020. PATENTED. OCT. 23, 1906.

A. FELLOW. METHOD OF OENTBRING LENSES APPLIOATIOK FILED APE.24.1905- -ssums- 112M 2.

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No. 884,020 PATENTED 001}.- za, 19 06.-

FELLOW.

METHOD OF OENTBRING LENSES 7 APPLICATION FILED Alf]!- 24. 1905.

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UNI ED STATES PATENT OFFICE. I

ARTHUR 'PE Low, or ROCHESTER, NEW YORK, ASSIGNOR To BAuscH &

= TION OF NEW YORK.

OMB OPTICAL COMPANY, OF ROCHESTER, NEW YORK, A CORPORA- METHOD OFCE'NTERING LENSES.

Patented ocaas, 1906.

Application filed April 24,1905. Serial No. 257,240-

To all whmn it navy concern.-

Be it known that I, ARTHUR PELLow, of Rochester, in the county of Monroeand State of New York, have invented certain new and .usefulImprovements in Methods of Center'- -.of my invention is to enable theaxes of lenses to be readily determined with extreme accuracy,particularly in lenses of slight curvature, and to provide a device bythe use of which the lenses may be quickly and conve'niently manipulatedfor centering, and

while the lens occupies its centered position it may be suitably marked.

To these and other ends the invention con- .sists in certainimprovements and combinations of parts, all as will be hereinafter morefully explained, the novel features being pointed outin the claims atthe end of the specification. I

In the drawings, Figure 1 is a side elevation of a lens-centeringmachine adapted for centering lenses in accordance with my invention.Flg. 2 is an elevation of the device looking from the opposite sidethereof, the eyepiece and reflector being shown in section.

Fig. 3 is a plan view of the device as shown in Fig. 2, the lens beingshown in section. Fig. 4 is a view in elevation, showing a device forcontrolling the clutch mechanism for the marking devices. Fig. 5 is asectional view showing the clutch mechanism and their op 'erating meansfor setting the marking de' vices into operation. Fig. 6 is a sectionalview on the line 6 6 of Fig. 3, showing the mechanism for bringing'themarking devices into operative position and for positioning the markingdevices. Figs. 7 and 8 are views in elevation and section, respectively,of the lens-supporting devices. Figs. 9, 10, and 11 are sectional viewsof the inking and marking devices; and Figs. 12 to 15 are diagramsshowing how lenses of different powers are centered.

The same characters of reference in the several figures indicate similarparts.

' In order to obtain the best results with 5 lenses, it is essentialthat they should be mounted with respect to their optical axes, and infinding the optical axis in accordance with .my invention the oppositesurfaces of the lens are each treated as a separate mirror orreflecting-surface to receive the rays from an object, and bymanipulating or adjusting the lens while the separate images reflectedfrom the opposite surfaces of the lens are under observation of theoperator these images may be brought into coincidence, and when this hasbeen accomplished the lens is centered with respect to its optical axis,and the marking device may be set into operation to mark the center thusobtained.

A device adapted for use in centering lenses in accordance with myinvention; is shown in the accompanying drawings as comprising astandard 1, mounted on the base 2 and carrying the horizontal support 3,7 the latter being of a length suitable to accommodate a lens-support 4at one end, the eyepiece 5 at the opposite end, and the movable markingdevice 6 intermediate of the eyepiece and lens-support. Thislens-support comprises anupwardly-extending standard carrying a plate 7,arranged perpendicularly of the support 3 and provided with the crossedslots 8 8 through which a dark screen may be sighted from the eyepiece 5as a back ground to render the images from the sur faces of the lensclearly visible to the observer. Extending through this plate are aseries of'supporting-pins, each. embodying a threaded portion 9, slottedat one end to per mit adjustment thereof in a direction trans vverselyof the plate and provided with a locknut 10 for securing it'in adjustedposition, and the forward end of each pin has a head 1 1, of hard rubberor other suitable material, applied thereto in order to avoid scratchingof the lens-surface by engagement therewith. I prefer to employ a seriesof four pins in rectangular arrangement and projecting equidistantlyfrom the plate, so that their 1 points all he in the same plane, becauselenses having spherical, cylindrical, or plane surfaces may be firmlyseated and ,centered;,.a, against them.

the position of the ob ect.

The eye piece may be of any suitable form, having a small sight-aperture12, and over this sight-aperture is fitted a casing 13, having a mirroror reflector 14 mounted on the pivots 15, so as to be capable of tiltinginto different positions to enable the light-rays to be directed uponthe lens while it is in positionagainst its support. In this mirror inalinement with the slght-aperture 12 and the central point of thelens-supporting pins a clear spot 16 is provided, forming an objectwhich will appear as a black image when reflected and as it is clearenables an observation to be had through it, and consequently theview-point of the observer will be from In addition to the object formedby the clear spot of the mirror it is preferable to provide the blackcross-lines 17 and 18, extending vertically and horizontally,respectively, of the mirror and intersecting at the clear spot, as thisrenders the object more readily diseernable and enables the axes ofcylindrical lenses to be determined, as will presently appear.

Arranged longitudinally of the support 3 and between the eye piece andlens-support are the ways 19 to receive the reciprocatory carriage 20,the latter having the uprights 21 thereon for supporting the shaft 22,on which a pair of radlally-arranged arms 23 are fixed.

These arms are connected at their free ends by the bar 24, through whicha series of cylinders .25 extend, each cylinder being provided with aplunger 26, having a spring 27 for operating it under a yieldingpressure in one direction, and the forward ends of the plungers areprovided with the marking devices 28, preferably composed of hard rubberor other suitable material and pointed toward their ends. These plungerscarrying the marking devices are so mounted that when they are inoperative position their marking devices will be in line with thehorizontal cross-line 18 of the mirror and with an imaginary lineextending horizontally through the central point between thelens-supporting pins, the central marking device being directly oppositeto the object 16 of the mirror, and the yielding action of the markingdevices enables them to accommodate themselves to plane or curvedsurfaces without movingthem out of center.

To the shaft 22 is fixed an operating-lever 29, arranged to. cooperatewith the roller or projection 30 on the relatively fixed standard 31 asthe carriage 20 is moved toward the lens-support to swing the markingdevices from the normal position, as shown in Fig. 1, to the operativeposition, as shown in Fig. 2, and as the motion of the carriage iscomparatively rapid a cushioning-stop or buffer is preferably employed,comprising, in the resent instance, a hollow post 32, fixed on t ecarriage and provided with a vertically-movable plunger 132, the head ofwhich is formed to engage the under side of the lever when the latter isswung into horizontal position by cooperation with the roller 30, thedownward motion of the plunger being cushioned by the spring 33 andlimited positively by engagement of the head thereof with the top of thepost. This cushioningstop serves to yieldingly arrest the motion of theoperating-lever for the marking devices when it is thrown by theroller30 and. to serve as a rigid support for the lever as the latter isdrawn down by the roller 30 as the latter traverses the upper surface ofthe lever dur ing the advancing movement of the carriage, and this willinsure the accurate positioning of the marking devices relatively to thecentered lens at each operation of the carriage, a cam or raised portion29'" being provided on. the lever, so as to engage the roller 30 duringthe return motion of the carriage to positively return the markingdevices to their normally depressed position.

The inking devices employed in connection. with the marking devicescomprise, in the present instance, an inking-roller 34, journaled in acasing 35,fixed to the carriage, and has a ratchet 36 connected theretoand arranged to cooperate with the} pawl 37 during the reciprocatorymotion of the carriage, causing the inking-roller to present newinking-surfaces to the marking devices prior to each marking operation.The inking-ro1ler is located to recelve and support the marking deviceswhen they occupy their normally depressed position, and at this time themarking devices and connected parts will not form an obstruction betweenthe lens and the object and observer.

Any suitable mechanism may be employed for setting the marking devicesinto operation at the desired moment, the mechanism employed in thepresent instance embodying a lever 38, pivoted to the standard or baseand operatively connected at its free end to the carriage 20, a pitman39 being connected to this lever and to a crank-pin 40, adjustablymounted in the crank-plate 41 to enable the travel of the carriage to beadjusted, the crank-plate being connected to a gear 42, meshing with apinion 43. This pinion 43 is mounted on the spindle 44 and between thebearings 45 and 46 thereof, a pin 47 being passed through a portion ofthe pinion am through a longitudinal slot in the spindle to permitrelative axial motion of the latter and to transmit rotary motionbetween the spindle and pinion. One end of the spindle is provided witha head 48, having projections 148 thereon, arranged to engage anddisengage those of the driving-pulle y 49 by a relative longitudinalmotion of the spindle, and the spindle is shifted longitudinally bymeans of the fork 50, pivotally connected to an operating-collar 150,resting in the groove 51 of the spindle and connected to the pivoted le-1 pressure to engage beneath the lever 52, and

thereby retain the latter in operated position, a projection 54 beingprovided on the crankplate 41 to disen' age the detent and the lever 52,permitting t e latter to be'returned to normal position under action ofthe sprin 55 after the marking device has complete its operation. In thecarriage-operating mechanism described continuous rotary motion isimparted to the pulley 45, and when it is desirable to 'set the markingdevices in operation the lever 52 is tilted to shift the spindle 44longitudinally, causin the cooperativelyarranged projections of t e head48 and the pulley 49 to engage, and thereby rotate, the spindle, rotarymotion of. the latter being transmitted to the pinion 43 and in turn tothe gear 42and crank-plate 41, and as the latter rotates the pitman 39is reciprocated, causing the lever 38 to impart reciprocatory 'motion tothe carriage 20, and during the op- 'erationof the carriage the markingdevices will be moved into operative position to mark the lens andsubsequently returned to a normal position out of alinement with thelens and the mirror, the knocking-off projection 54 of the crank-platebeing so placed that the motion of the carriage is interrupted while-themarking devices occupy their normal inoperative position.

In centering lenses in accordance with my invention the principlesinvolved are essentially the same for the. different kinds of lenses,and therefore in the accompanying diagrams the method employed fordetermining the axes of spherical lenses is illustrated, the lens w, theaxis of which is unknown, being-held by the hand of theoperator firmlyagainst the supporting-pins, and while the lens occupies such a positionthe mirror 14 is tilted, sov that an image of the object thereon isplainly visible as reflected from each surface of the lens, a darkscreen being arran ed behind the lens to render the image more istinct.Should the lens occupy a position similar to that shown in Figs. 12 and14, its axis A B will be deflected, and consequently the incident ray a,emanating from the object at M and striking the anterior surface y ofthe. lens at the normal thereto, will be reflected back to the eye ofthe observer at 0 and will appear as a virtual image I, which ap earsentirely separate and does not coinci e with the image I, reflected fromthe posterior surface 2 of the lens by the incident rayb, emanatingfromthe object on the mirror at m, and only one image for each surfacewill be observed, as the rays falling on the lens-surfaces at any otherangle than the norvand this will occur when t mal will not be reflectedback on themselves and to the observers eye. The position of the lens a:on'the supporting-pins may now be shifted by manipulation until theseseparate images reflected from the anterior and posterior surfaces ofthe lens a pear to coincide,

lie incident rays (1 and b from the object striking the anterior andposterior surfaces of the lens at the normal are in alinement with thecenters of curvature R and R of the two lens-surfaces, as indicated inthe diagrams, Figs. 13 and 15, any other rays of the object, such as cand (1, meeting the lens-surfaces y and 2, respectively, being deflectedsubstantially in the directions indicated by the lines 6 and f and ofcourse would not be visible to the observer. While the lens is held incentered position, the

marking devices are brought into action by operation of the lever 52,causing the carria e 20 to advance toward the centered lens, an in doingso the operating-roller 30 will cooperate with the lever 29 to swing thearms 23, carrying the marking devices into operative position, andasthese marking devices are supplied with inkand operate directly in theline of vision when the lens is centered the central marking device willmark the optical center of the lens, the continued operation of thecarriageeoperatin mechanism causing the carriage to be with rawn and themarking devices withdrawn from the line of vision.

In centering cylinder or sphero cylinder lenses the ,method aboveoutlined is employed; but unless the lens is centered ac cording to theaxis of the cylinder the crosslines embodying a part of the object willappear in'the images as though they were par: tially revolved inopposite directions, and conse uently byrotating thelens in thepro erdirection until these cross-lines correspon in their directions andcoincide the axis of the cylinder may be readily found, andas a seriesof three markers is generally employed the central marker will mark theoptical center of the sphere, and the markers at either side thereof andin line therewith will mark th direction of the axis of the cylinder. 3

Of course the method and the apparatus embodying my invention are alsoadapted for testing lenses having either lane, spherical, or cylindricalsurfaces at either or both sides, as the reflected images from theopposite surfaces of the lenses when brought into coincidence in themanner hereinbefore described will accurately locate the optical axesofthe lenses, and the peculiar arrangement of the lens-supporting insinsures a firm and proper seating of the p ane and spherical surfaces ofthe lenses at all positions, and the cylindrical surface when the lensis in centered position and the yielding arrangement for the markingdevices enables them to apply the ink to the surfaces, of lenses havingwidelydiffering curvatures that may be either concave or convex.

formed on lenses of different classes and powers without requiring anyadjustment or focusing-of the apparatus.

vice I have shown is adapted for centering cut into their desiredoutline, and when it is desired .to center lenses with respect to theiroutlinesuch, for example, as to determine the optical axis of thecylinder of the usual elliptical eyeglass-lens with respect to its eofens metrical axisany desired rotatable support or holder for positioningthe elliptical lens may be em' loyed, and by the use of the methodherein efore described the optical axis may be readily determined.

The apparatus described in the foregoing description is particularlyadapted for use in; centering lenses according to the method em-jbodying my invention; but this method may be performed by the aid ofapparatus or de-j vices differing from that shown, and there-' fore theapparatus or mechanical devices shown are not claimed herein, but arereserved for a divisional appl catlon.

I claim as my 1nvent1on 1. An improvement in the art of centering lenseswith respect to their optical axes, con- 1 sisting in directing the raysof an object from a given view-point to the surfaces of the lens, andthen adjusting the lens until the images of the object appear tocoincide.

with respect to their optical axes, consisting in directing rays from anobject on the surfaces of a lens, and adjusting the lens while theseparate images from the opposite surfaces of the lens are beingobserved from the object as a view-point until the images appear tocoincide.

3. An improved method of centering lenses with respect to their opticalaxes, consisting in reflecting the rays from a mirror having an objectthereon upon the surfaces of the lens to obtain a separate image fromeach surface of the lens, and then adjusting the lens until the separateimages appear to coincide.

4. An improved method of centering lenses with respect to their opticalaxes, consisting in directing the rays from an object upon the surfacesof a lens, adjusting the lens until the images of the object from theopposite surfaces of the lens appear to coincide, and mark ing the axisthus obtained.

5. An improved method of centering lenses with respect to their opticalaxes, consisting in adjusting an object so that an image thereof fromeach lens-surface may be plainly observed, and then adjusting the lensuntil the images appear to coincide.

. ,6. An improved method of centering cylindrical lenses with respect totheir optical axes, consisting in directing the rays from. an objecthaving a given configuration upon the surfaces of a lens, and rotatingthe lens until Of course it will be understood that the dethe imagesfrom the opposite surfaces of the lens appear symmetrical and incoincidence.

7. An improvement in the method of centering lenses with respect totheir optical axes, consisting in directing rays of light from an objectto the surfaces of a lens to produce a separate image for eachlens-surface, adjusting the lens while both images are under observationfrom a given view-point, until the images appear to coincide andapplying a mark to the lens-surfacc at apoint in alinement with theimages observed.

8. An improved method of centering lenses with respect to their opticalaxes, consisting in directing light-rays from a luminous object to thesurfaces of a lens to produce a separate image from each lens-surfaceacting as a mirror, adjusting the lens while both images are underobservation from the object as a viewpoint until the images appear to bearranged in alinement with the view-point, and applying a mark to asurface of the lens at a point appearing to be in alinement with theimages observed.

9. An improved method of centering lenses, consisting in reflectinglight-rays from a luminous object onto the surfaces of a lens having adarkened background to produce a separate image for each lens-surfaceacting as a mirror, and adjusting the lens while the im ages are underobservation from a given viewi point until the images appear tocoincide. 2. An improved method of centering lenses;

the cross-lines of the images appear to intersect.

11. The method of centering lenses, consisting in supporting the lens inposition with a background to form mirrors or reflectors of thelens-surfaces, directing the light-rays from a luminous object upon thelens-surfaces to produce a separate reflected image from eachlens-surface, and adjusting the lens while the images are being observedfrom a given view- I and shifting the position'of the lens while thepoint until the images appear to coincide. images reflected therefromare under obser- I0 12. The method of centering lenses,consistvationfrom the object as a view-point, until ing in positioning a lens beforea suitable the images appear to coincide.

background to form mirrors or reflectors of ARTHUR FELLOW. thelens-surfaces, adjusting a mirror with an Witnesses: object thereon sothat an image thereof ap- CLARENCE A. BATEMAN,

,pears to be reflected from each lens-surface, WALTER B. PAYNE.

